Interpolymers of vinyl chloride, higher alkyl acrylate and dialkenyl ester of olefinic dicarboxylic acid



Patented Aug. 26, 1952 UNITED? STAT INTERPOLYMERS OF VINYL MCHLORIDEQ HIGHER. ALKYL ACRYLATE" AND DI:-

BQXYLIC ACID Robert J. Wolf, (llevel'and, Ohio, assignor to The B.-F-.' Goodrich Company, NewYork, N. Y, a. corporationof New York no Drawing. Application April 25,1959,

SerialNo. 153,054

i i Claims.

' The present invention relatestoiinterpolyiners obtained by the polymerization of a monomeric mixture containing at. least three monomeric components, each in particular proportions, one of which is vinyl Chloride, another of which is 3 1 211 a yl acrylate suchas an octyl acrylate, and another of which. is dialkenyl ester of an olefini'c dicarboxylicacidjsuch as di'allyl maleate, whichinterpolymerspossess. various new and improved properties, especially in regard to their inherent plasticity and ease of processing com' bir ied withlharclness and excellent strength in final end usaand it pertains, particularly to threecomponent interpolymersor tripolymers of these. threetypes of monomers which ar so inherently plasticized in nature. as to be'fprocessed and made into excellent'films, sheets, rods, tubesandplates withoutthe addition of plasticizers. Vinyl resins such as polyvinyl chloride and copolymers. of vinyl chloride with various other monomeric materials such asmethylacrylate, vinyl. acetate, vinylidene chloride and diethyl fumanate are well known: to, the art. and in their plas'ticized form are .widely nsd innumerous. a p i a i ns Th ihamq a i vinyl in is. itself relatively ama dgnumy at. normal tern.- r am e d. is? n r l in apa l 30f being eas y s jected t ac e s n f c s SW11- as milling; calendaring, extruding, e '1; without heating the resin to high temperatures, Addition of plasticizers, which generally are. of the oily steretyperlow softening pointoflthe semr s t su t e Pr e se l n a ay be 9 carried 7 out. at lower. tem eratures However, add o of p e tic ertepn ni n y e rs th room temperature hardness'flo f the plasticized vompd it eh and e i n l makes t e i somewhat taqky. It is. thus. .difiicult to. achieve a plasticized vinyl resinoomposition. which is easily processed at moderate temperatures yet. which. in the final end product will have'themanyetime's desirable properties of hardness, rigidity,,etc.

There. areiadditilonal disadvantages necessarily attending; the use'of plasticizers in vinyl resin compositions; The plasticizers. commonly employed' even when thoroughly mixed with the resin have a pronounced tendency to bleed or migrate to the surface of the composition where they are lost through wiping; washing orzvolatil'ization with the result that the composition gradually stiffens and hardens and consequently fails in service; Moreover; the-migration of plasticizer desJ IDYS adhesive bonds between the plastic and othersurfacesand mars varnished surfaces in contact w'ith the plastic: An economic disad' tlqve lt o u e num r us a es WW .2 vantage is that the oily plasticizer materials normally be incorporated into a vinyl resin an expensive and time-.consumingor mixing op eration. It i S 2[ primary object of this invention, therefore, to provide anew class of vinyl resins each member of which is possessed of inan'yo td sira le p op t s o inq l vinyl eris whic i nhe ntlr roq s b'le t v1. quire the addition ofplasticizers during process ing or to achieve plastic properties imth e final produ nd wh on ha c o ntea it m ore durable serviceable and otherwise sira Anotherob ect is to provide a-vinyl plas is no u c o osso plas it by we ti'on, bleeding onextraction ofplasticiaer is, also an object totprovide' new vinyl resins wh a e ea ly subjected o proce ng operat c mode atelyj l' v tedtemperatu e xces ively softer tacky and ha e .5. 1. stiffness, rigidity and high strength at normal temperatures.

I have discovered that by polymerizing, preferably in an aqueous medium, monomeric mixtures containin at least three components, each in definitepromrtionsone being vinyl chloride) another of which isYahi'gheralkyl' e'stero ylic acid such as an octyl acrylate, and thethird a dialkenyl ester of an olefinic dicarboxylic acid as hereinafter defined, Iam able to obtain novel interpclymer havin thetm e tie neeessarv ier achiev n theale ve and othe xeibj The r a i e propo ti n o rmoncmets h ck; are emplo ed in the prod ci e q'o m ii mers aresom ewhat crit al since t e ties ed plcner ies re not ec red in any premay vary within eertainqlimits; In t meric mixture I have found it necessar; to from Ira-to 95% by wei ht-ofvi-ny a-c ioride. ra 5. to 651% by. weis-htofhiehe a1l nlary a and from. 0.01 to 12.01% by weight of ,dialken ,er with at least; 90% byawei-ght orthetmpncmeric mixturemade up: ioi: these three: ingredients:- Other: monomeric materials suchhas; vinyli'dene chloride, diethyltfumarate vinylbenzoateracryloe nitrile, styrene, isobutylenelower. alkyltaerylates such as-methyl and: ethyl. acrylatev and othe'mare; i i desirable, utilizable to theTextent 01.10% :by weight of i the monomeric 'mijxture without snb stantiall y afi'eeting the desirable 3 properties: Partic'ularlsr"valuable are thosei r'i-te polyniers or tripolymers made from three component m "o?- mericf mixtures containing from} 5( l" i o by Weight of vinyl chloride, from 15 to 50 b 3iweigfit of acrylic acid in which the alkyl group con.

tains a chain of from to carbon atoms. I have'found that the degree of plasticity or inherent processability imparted to my new interpolymers by these higher alkyl acrylates corresponds roughly with the observed degree of.

plasticization imparted to ordinary .vinyl resins by addition thereto of ester type plasticizers containing similar alkyl groups. For example, di-Z-ethylhexyl phthalate is an excellent plasticizer for vinyl chloride polymers and 2-ethylhexyl acrylate has been found to produce interpolymers possessing inherent processability to a high degree. Illustrative higher alkyl acrylates within the above class utilizable in this invention include n-amyl acrylate, n-hexyl acrylate, the isohexyl acrylates, isoheptyl acrylate, n-heptyl acrylate, capryl acrylate (l-methylheptyl acrylate), n-octyl acrylate, Z-ethylhexyl acrylate, isooctyl acrylates such as fi-methylhexyl acrylate, n-nonyl acrylate, isononyl acry lates such as 3,5,5-trimethylhexyl acrylate, ndecyl acrylate and others.

It is greatly preferred to employ higher alkyl acrylates in which the alkyl group contains a total of 8 to 10 carbon atoms and possesses a carbon chain of 6 to 10 carbon atoms. Compounds within this class are 6-methylhepty1 acrylate, 3,5,5-trimethylhexyl acrylate, 2-ethylhexylacrylate, capryl acrylate, n-octyl acrylate and others. This preferred class of higher alkyl acrylates has been found to impart a high degree of inherent processability to the interpolymers of this invention and n-octyl acrylate appears to be the most effective in this respect.

The dialkenyl esters of olefinic' dicarboxylic acids utilizable in the production of my new interpolymers possess, in general, the formula methylenegroup attached by a double bond to a carbon atom, that is, the structure Esters of this class include the diallyl, dimethallyl, diethallyl, divinyl and di-isopropenyl esters of maleic and fumaric acids as well as mixed esters such as allyl methallyl maleate etc. Diallyl maleate because of its availability, lower cost and its ability to produce superior interpolymers according to this invention is the preferred dialkenyl ester.

It is preferred to carry out the polymerization of monomeric mixtures to produce my new interpolymers in an aqueous medium. When an aqueous polymeric dispersion is the desired endproduct the polymerization is preferably carried out in an aqueous emulsion in the presence of an emulsifier. In addition to the preferred aqueous emulsion method, the mixture of monomers may be polymerized in aqueous medium containing a colloidal protective substance such as gelatin, bentonite clay, polyvinyl alcohol, polyacrylic acid, and others to obtain a fine granular or pearl-like polymer. The latter aqueous suspension method is a satisfactory method for producing polymer intended to be processed directly in the solid form. The mixture of mono- 4 mers also may be polymerized in a suitable solvent or in mass in the absence of a solvent or diluent.

Whatever method of polymerization is employed a catalyst'is generally required. 'The catalyst may be any of the substances commonly employed for the polymerization of vinyl compounds. Actinic radiation may be employed, as

well as the various peroxygen compounds such as hydrogen peroxide, benzoyl peroxide, 0,0- dichlorobenzoyl peroxide, caproyl peroxide, caprylyl peroxide, pelargonyl peroxide, cumene hydroperoxide, tertiary butyl hydroperoxide, 1- hydroxycyclohexyl hydroperoxide, tertiary butyl diperphthalate, tertiary butyl perbenzoate, sodium, potassium and ammonium persulfate, sodium perborate, sodium percarbonate, and others. The oxidizing catalyst may be used in combination with a reducing substance such as a polyhydroxy phenol, sodium sulfite and the like in what is commonly referred to as a redox polymerization. Both the oxidizing and redox catalysts may be activated with small amounts of a heavy metal salt such as silver nitrate, copper sulfate, various ferric salts, etc.

In some instances it may be desirable to control or adjust the hydrogen ion concentration of the polymerization mixture, which tends to become more acid because of liberation. of hydrochloric acid during polymerization; It is preferred therefore to add a buffering substance to the reaction mixture. For this purpose such substances as sodium bicarbonate, sodium carbonate, disodium phosphate, trisodium phosphate, ammonium hydroxide, sodium hydroxide, the amino-substituted alcohols such as 2-amino- Z-methyl-l-propanol and the like, and others are suitable.

When the monomeric mixture is polymerized in aqueous emulsion a wide variety of emulsifying agents may be utilized. Suitable materials are, for example, ordinary soaps such as sodium oleate, potassium palmitate, sodium myristate, ethanol-amine laurate, and rosin and disproportioned rosin. acid soaps; synthetic saponaceous materials such as the salts of alkaryl sulfonic acids, or of acid sulfuric esters of long chain alcohols such as sodium isopropyl napthalene sulfonate, sodium lauryl sulfate, and the sodium salts of sulfonated petroleum fractions and others.

While the polymerization maybe carried out under an atmosphere containing air or oxygen, the rate of reaction is ordinarily faster under an atmosphere substantially free of oxygen and hence polymerization in an evacuated vessel or under an inert atmosphere is preferred. The temperature at which the reaction is carried out is not critical, it may be varied widely from -3( C. to C. or higher, though best results are generally obtained at a temperature in the range of 0 C. to 70 C. a

In order to minimize variation in the rate of reaction and to maintain a given proportion of each of the three types of monomers in the reaction mixture throughout the reaction cycle it is sometimes desirable to introduce the acrylate monomer and/or the dialkenyl ester in increments or g ad ally during the course of the polymerization. The acrylate and the diallyl maleate may be premixed and added to the reaction vessel at a rate consistent with that at which these monomers are used up in the reaction.

The preparation of the interpolymers of this invention, their properties and representative a ooagea-e usesnwilr bet-more clearly described in the: following -speeific examplesuwhich are intended merely:

Ewample 1 Aitripolymen isiprepared byrthe polymerization:

oI F'the monomeric materials-L contained in a"; reraction mixture having theifollowing composition:

Material,

Vinyliehloride; r. 55:0 Is'ononylacrylate- 45. v Dlally'l maleate; 0.01 POtflSSiUmZPerSUHME; 0-:70 Emuls' en.-- m 4.0. Ammonia 0520 Water.- 9s.

The: water; potassium: persulfateand emulsifier are: charged totheereactor which then is sealed and evacuated: Theammonia and monomers 'are therriaddedand the: resultant: mixture" agitated and heated' to C; After" 17 hours of reaction:

at::45..". thereresults a-:fluid:stable-latex containing.:5'0% tota1'so1ids.

Aiportionof the latex is coagulatedby the usual salte-acidl method and the resultant coagulumd'riedrin an air oven: at150 C; Thedrygranular polymer is. 'f ound to band into smooth clear sheets without plasticizer on' a .two -roll plastic .mill' the rolls-:"ofl-which: are maintained at only 150 F. Theigranularpolymer' fiows with such ease that azz disc-can be -pressa-molded from the polymer in only 3fminuteswat 140 1-0; The-press-molded disc is non-tacky; completely fused, and is strong and flexible; having a hardness of i durometer A at 30 0:. A copoly-mer: similarly prepared from a mixture: consisting of I 55 parts of: vinyl chloride andf-454parts of: isononyl acrylate; issli'ghtly tacky andihaszarhardness of about '75ldurometer A.

The polymerofiExample liorms aclear; water-- white solution in tetrahydrofuriuralirom which excellenta clear. non-tacky: films can be cast by drying: andfusing at: 100' to 150C; The'latex of Exampler 1; however; forms: excellent clearnon' tacky filmszwhen dried' at room temperature. The:

films cast fromboth the :tetrahydrofurfura-l "solution and .the latex arefound" to be exceedinglystableto the-effects of light and heat -by atest utilizing-the tendency of vinyl chloride polymers 1 to become' colored" and opaque when heated or exposed to ultra-violet light; Accordingrto-this test a film of the polymer is deposited from' solution-r on: a clean glass microscope slide and the light-transmitted through the coating measured liothbefore -and afterexposure: Theper cent 1 light transmitteclis takenas a qualitative indi cation of the light'or'heat stability of the polymer.

Bythis :method after-being heated 24- hours at 1'15" C. the polymer of-Example 1 has a heat sta maieate' content of-the: monomeric mixture of Example lis increasedto' 0.05 part: The tripoly mer is slightly harder; 83' durometer A, yet is easily mill'edj' calenderedj extruded or molded by injection without, the. addition of," plasticizer. Whentthe dia1lyl"maleate content ishincreased to 0310*part; the resulting polymer ha a hardness 6 85'rdurometer Aizyetiis": more easilykprocessablda than: either ofthe other'tripolymers; Forexam rile; films cast from. this polymer-i int solutionion directly from: it's: latex: require heating; onlyrto'z 100 C. to be completely iusediandcl'ear: With 0.35 part of diallyl maleate, a tripolymer is produced having a hardness of 87 durometer A, a tensilestrength of" 1,9'00 pounds 'per -squa're-i'nch, an elongation of 250 and ar modulus a't' I00 elongation of-' 1 ,100 pounds per square" ir'icih;

Examplei' A tripclymer isprepared in the manner of 'Ex ample -1 fronra monomeric :mixture consistingwof 55 parts byweight of vinyl chloride; 45 parts ty- Weight of isononyl'acrylate; and 0.5'part by weight of diallyl maleate; In 16' hours at45 C. 'the re action has reached substantial? completion w-ith the formation of a latex containing- 503% totalsolidsar. The solid polymer derived? from the latex: has a hardness of QOdurometenA' yet: it bandssmoothly without pl'asticizer on" aplastic= mill having itsrolls maintained at onlyl'BOP F." The polymer is easily extruded without plasticizer' to" form. stronglrather stiff tubes: and rods-and calendered (with0utplasticizer) on" a four rollcalender having its rolls maintained at 200 F. toform a smooth" stifi: film of "10 m: i in: thicknesshaving extremely goodilexural properties and high tear strength. Whencalender'edon a fabric.

the polymer of. this example forms a dr-y taclt free'coating which when folded or rubbed 'on' itself has the characteristic feel and creak s0 familiar inleather goods A tripolymer is prepared by the polymerization of a reaction mixturezrhavingz the following composition:

The polymerization is conducted at 509 C. to produce a stable latex containing 52.8 %;total solids: When the latex is coated on a smooth surface: and dried at room-temperature(30' C.) a-clear filmis deposited which mayleasily be stripped ofin the casting surface.- When; however; theJateX filmis heated .ior 10 minutesat=l35 C., an -excel-- lent ..c1ear film is obtained having-.ahardness-of v durometer A, a ltensile'streng-th of .1900 lbs./ sqn in., an elongation of 260%; and a" modulusrat'i elongation of.1300 lbs/sq. in. Y

The solidltripolymer obtained by the coagulan tionof the, latex of vExample 3,;mil1syery easily withlgood body on a millhavingitsirolls main tained ,at.only 150 By the Clash-Bergfiexb; b'ility temperaturetest, which measurestlhe tem-- perature at which a sample of-polymercompost tion exhibits a given torsional. loading, the ltri-- polymer of this, example has a: flexibility"tem--' :perature at ;00'01b's./sq. in. loading 015-. 2'7 C. By comparison a sample of polyvinyl-chloride plasticized with BWpartsbyWeightof dial-ethylhexyl phthalate so" as to have a hardness of 85-1 durometer. A has a Clash-Berg flexibility tem p'erature. of only -22.5-'C1 A comparableicopoly mer of 65 parts by weight: of; vinyllchloride land 35 parts of 2-ethylliexyl"acrylatehas a hardness of only 55A and a flexibility temperature of Example 4 I A tripolymer is prepared by the polymerization in aqueous emulsion at 50 C. of a monomeric mixture containing 65% by weight of vinyl chloride, 34% by weight of 2-ethylhexyl acrylate and 1% by weight of diallyl maleate and is obtained in the form of a latex containing in excess of 50% total solids. The latex is utilized directly for the casting of latex films. When the latex is cast on a clean surface and dried at room temperature there are formed good clear films. Whensuch a film is heated for 10 minutes at 135 C. an excellent clear film is obtained having a tensile strength in excess of 2000 pounds per square inch and an elongation of about 140%.

The solid tripolymer derived by coagulation of thetripolymer latex of this Example 4 is milled without plasticizer on a mill having the rolls maintained at only 175 F. When the tripolymer is press molded without plasticizer for 1 minute at 140 F. a clear completely fused disc is obtained. The hardness of the tripolymer sheet is in excess of 100 d urometer A, however, the tripolymer is easily extruded without plasticizer to form hard and rigid tubes and rods.

Tripolymers made in a similar manner utilizing monomeric mixtures containing 1 and 2% by weight of diallyl maleate are progressively harder and stiffer in nature yet can be processed at moderate temperatures of 200 to 250 F. without plasticizer.

Example 5 Tripolymers may be made with considerable variation in the amount of vinyl chloride and higher alkyl acrylate employed. For example, a tripolymer resulting from the polymerization in the manner of the preceding examples of a monomeric mixture containing only 35% by weight of vinyl chloride, 65 by weight of n-octyl acrylate and 1 by weight of diallyl maleate has exceptional processability without plasticizer yet is not excessively soft or tacky.

On the other hand, a tripolymer made from a monomeric mixture consisting of 80 parts by Weight of vinyl chloride, 20 parts by weight of 2-ethylhexyl acrylate, and 0.10 part by weight of diallyl maleate is a relatively hard (98 durometer A) and rigid material having outstanding processability. The tripolymer is formed into a smooth clear band by milling for eight minutes on a two-roll plastic mill having its rolls maintained at only 200 F. A standard commercial grade of polyvinyl chloride when plasticized with 50 parts by weight per 100 parts of resin of di-2- ethylhexyl p'hthalate (so as to have a hardness of 85 durometer A) requires a milling cycle of minutes at 280 F. Similarly, the tripolymer is easily extruded in a lastic extruder having a rear cylinder temperature of 200 F. and a front die temperature of 210 F. while the softer polyvinyl chloride composition requires corresponding temperatures, respectively, of 340 F. and 400 F.

In addition, the tripolymers extreme case of processing is shown by its being easily calendered to a 10 mil thickness on a four-roll calender having all four rolls maintained at only 240 F. while the plasticized polyvinyl chloride composition requires a temperature of 350 F. 1

The latex ofthis /20/010 tripolymer when used directly to form unsupported latex cast film,- forms excellent, clear film merely by drying at room temperature. When heated for 10 minutes at 135 0., the resultant film is found to possess a tensile strength of over 3000 lbs/sq. in. and an elongation of 250%. The tripolymer film is tough, hard and flexible and is admirably adapted to use as a food packaging material.

'ExampZe 6 The previous examples have been concerned with tripolymers made from monomeric mixtures containing only the three essential ingredients; however, other monomers may be utilized to produce multi-component interpolymers. For example, a mixture consisting of 55 parts by weight of vinyl chloride, 35 parts by weight of isononyl acrylate, 10 parts by weight of styrene and 0.2 part by weight of diallyl maieate polymerizes in aqueous emulsion to produce a tetrapolymer easily processable without plasticizer and having good heat and light resistance. Similarly, polymerization of a mixture consisting of 60 parts by weight of vinyl chloride, 20 parts by weight of isononyl acrylate, 20 parts by. weight of n-amyl acrylate, and 0.4 part by weight of diallyl maleate results in a tetrapolymer having a' high degree of processability requiring molding for only 1 minute at 140 C. (without plasticizer) to form a completely fused, clear but stifi disc or sheet. Acrylonitrile, methyl acrylate, ethyl acrylate, vinylidene chloride, vinyl acetate, vinyl benzoate, isobutylene and other monoolefinic monomers may be substituted for the styrene as above in amounts up to 10% of the monomeric mixture with substantially similar results. However, since the use of such other monomeric materials does not result in additional advantageous properties it is of course generally preferred to produce.

interpolymers from monomeric mixtures containing only vinyl chloride, a higher alkyl acrylate, and diallyl maleate.

When the above examples are repeated using other dialkenyl esters of the class described'herein such as dimethallyl maleate and diallyl fumarate, substantially equivalent results are secured.

While the invention has been described with particular reference to certain preferred embodimerits thereof it is possible to make variations and modifications therein without departing from the spirit and scope. of the invention as defined in the appended claims. 5 x

Iclaim:

1. An interpolymer made by polymerizing a mixture of monomeric materials comprising from 50 to by weight of vinyl chloride, frornlO to 50% by weight of an alkyl ester of acrylic acid in which the alkyl group contains from 8 to 10 carbon atoms and posseses a carbon chain of from 6 to 10 carbon atoms in length and from 0.1 to 2.0% by weight of an ester of the formula wherein each R represents an alkenyl radical of from 2 to 5 carbon atoms containing the structure CH2=C at least by weight of the said monomeric mixture being composed of the enumerated monomeric materials. r

2. A tripolymer made by polymerizing in aqueous emulsion a mixture of monomeric materials consisting of from 50 to 85 parts by Weight'of vinyl chloride, from 15 to 50 parts by weight of 9 7 an alkyl ester of acrylic acid in which the alkyl group contains from 8 to 10 carbon atoms and possesses a, carbon chain of from 6 to 10 carbon atoms in length and from 0.1 to 2.0 parts by weight of diallyl maleate.

3. A tripolymer made by polymerizing in aqueous emulsion a monomeric mixture consisting of from 50 to 85 parts by weight of vinyl chloride, from 15 to 50 parts by weight of 2-ethylhexyl acrylate and from 0.1 to 2.0 parts by weight of diallyl maleate.

4. A tripolymer made by polymerizing in aqueous emulsion a monomeric mixture consisting of .from 50 to 35 parts by weight of vinyl chloride,

from 15 to 50 parts by weight of 3,5,5-trimethylhexyl acrylate, and from 0.1 to 2.0 parts by weight of diallyl maleate.

5. A tripolymer made by polymerizing in aqueous emulsion a monomeric mixture consisting of REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,202,846 Garvey et al June 4, 1940 2,496,384 Nie Feb. 7, 1950 OTHER REFERENCES Rehberg et 2.1., Ind. Eng. Chem, 40,

1429-33 (Aug. 1948). 

1. AN INTERPOLYMER MADE BY POLYMERIZING A MIXTURE OF MONOMERIC MATERIALS COMPRISING FROM 50 TO 85% BY WEIGHT OF VINYL CHLORIDE, FROM 10 TO 50% BY WEIGHT OF AN ALKYL ESTER OF ACRYLIC ACID IN WHICH THE ALKYL GROUP CONTAINS FROM 8 TO 10 CARBON ATOMS AND POSSESS A CARBON CHAIN OF FROM 6 TO 10 CARBON ATOMS IN LENGTH AND FROM 0.1 TO 2.0% BY WEIGHT OF AN ESTER OF THE FORMULA 